The aim of this proposal is the early and accurate identification of the infant at very high risk of neurologic deficit due to perinatal hypoxia so that intervention to alleviate the affects of hypoxia can be appropriately utilized. Perinatal asphyxia is the major cause of cerebral palsy, mental retardation and childhood epilepsy. The initial hypoxic insult initiates a chain of events which cause progressive cellular damage and leads to further deficit. Neonatal seizures are an early indicator of hypoxic insult - yet 70% of infants with seizures do well. Our previous work suggest that for the neonate who has had a seizure, a multivariate predictive formula which included events prior to or at the time of the seizure such as the Apgar score, the need for resuscitation, and the time of onset and duration of seizure could distinguish the infant who is likely to have neurologic deficit from those likely to be normal. Accurate identification will allow the development and appropriate utilization of medical interventions which could prevent the progressive effects of hypoxia, and avoid some or all of the subsequent neurologic deficit. Our previous predictive formula was developed on babies born in the 1960's and must now be validated and refined for babies born and cared for in today's dramatically different intensive care environment. This proposed study will prospectively enroll a community based population of 200 infants with neonatal seizures and follow the infants to age 2 when severe mental retardation, cerebral palsy and epilepsy can be accurately diagnosed. Sophisticated statistical analysis of the perinatal variables will allow the development of a formula which will predict outcome in today's infants. This will permit targeting of intervention to appropriate infants and avoid high risk intervention in infants likely to do well.